A wireless communication system may use a relay station (RS) to expand cell coverage and to improve transmission performance.
When a base station (BS) provides a service to a user equipment (UE) located outside the coverage of the BS by using the RS, the cell coverage can be expanded by allowing the RS to relay both a control signal and a data signal between the UE and the BS.
In addition, when the UE is located inside the coverage of the BS, transmission performance can be improved so that the UE can further reliably communicate with the BS by allowing the RS to amplify a data signal between the BS and the UE and to deliver the amplified data signal to each receiving end. In particular, the RS may be necessary when the UE is located in a shadow zone while being located inside the coverage of the BS.
That is, the institute of electrical and electronics engineers (IEEE) 802.16j standard allows a UE located outside the coverage of a BS to be able to receive a signal by using an RS, and allows an UE located inside the coverage of the BS to be able to configure a high-quality path with a high level of an adaptation modulation and coding (AMC) scheme, thereby increasing system capacity by using the same radio resource.